Cancer of the skin (non-melanoma and melanoma skin cancers combined) is the most common of all cancers accounting for more than 50% of all cancers. Melanoma accounts for about 4% of skin cancer cases, but causes about 79% of skin cancer deaths. The number of new melanomas diagnosed in the United States is increasing. The American Cancer Society estimates that about 55,100 new melanomas will be diagnosed in the United States during 2004. About 7,910 people in the US are expected to die of melanomas during 2004. Since 1973, the mortality rate for melanoma has increased by 50%. Much of this increase has been in older people, mostly white men. Because of education and early detection, deaths from melanoma are now increasing less rapidly in white men and have leveled off among white women.
Melanoma begins in the melanocytes. Because most of these cells keep on making melanin after becoming cancerous, melanoma tumors are often brown or black. Melanoma most often appears on the trunk of fair-skinned men and on the lower legs of fair-skinned women, but it can appear other places as well. While having dark skin lowers the risk of developing melanoma, it by no means eliminates such risk. Melanoma is almost always curable in its early stages. But it is also likely to spread to other parts of the body. Melanoma is much less common than basal cell and squamous cell skin cancers, but is far more serious.
Currently, treatment options for melanoma include surgery, radiation, chemotherapy, interferon-alpha treatment and vaccine therapy. All of these treatment options are not without problems. For example, surgery is invasive and may leave undetected cancer behind. Radiation and chemotherapy have toxic effects on the patient. Interferon-alpha and vaccine therapies are effective only for a subset of diagnosed patients.
Another prominent cancer of epithelial origin, also noted for its invasiveness, is ovarian epithelial cancer. It is often asymptomatic at its early stages and is only discovered once the disease has progressed to a later stage that manifests as the appearance of destructive growth in primary tumors, and accumulation of ascites in the peritoneal cavity.
Many other cancers generate invasive cells. Non-limiting examples are breast ductal carcinoma (Huang et al., Cancer Res. 64: 2712-2716, 2004; Goodman et al., Clin. Exp. Metastasis 20: 459-470, 2003; Kelly et al., Mod. Pathol. 11: 855-863, 1998; Ariga et al., Int'l J. Cancer 95: 67-72, 2001; Kelly, Drug Resist. Update 8: 51-58, 2005) and gastric (Mori et al., Oncology 67: 411-419, 2004; Okada et al., Oncology 65: 363-370, 2003), colonic (Iwasa et al., Cancer Lett. 227: 229-236, 2005), and cervical carcinoma (Jin et al., Anticancer Res. 23: 3195-3198, 2003). These invasive cells tend to drive the growth and spread of tumors, and are often metastatic.
What is needed are new materials and methods for the treatment of people diagnosed with cancer, including but not limited to melanoma and other carcinomas.